If you see a low-flying helicopter buzzing over East County wetlands next week, it's not an inspection — it's the county fighting mosquitoes.

San Diego County Vector Control will conduct its first routine aerial larvicide drop of 2026 on March 24, targeting up to 50 local waterways where mosquitoes commonly breed. The monthly flights continue through October, treating sites across the county, including areas throughout East County.

The larvicide used is a solid, granular product and is described by county officials as safe for people, pets, and wildlife. The treatment targets mosquito larvae before they mature into biting adults — a far more effective approach than trying to eliminate mosquitoes after they have hatched.

The county has relied on aerial treatments since the early 2000s, when West Nile virus first appeared in the region. While West Nile primarily affects birds, it can spread to humans through mosquito bites. San Diego Vector Control also deploys ground crews, boat treatments, and monitors around 1,600 potential breeding sites each year.

Residents can help at home by following the county's "Prevent, Protect, Report" guidelines: dump or remove anything that holds standing water — plant saucers, buckets, old tires, and gutters are common culprits. Free mosquito-eating fish are available for backyard ponds and unmaintained pools by contacting the Vector Control Program. To report increased mosquito activity or dead birds, call (858) 694-2888 or email vector@sdcounty.ca.gov.